I believe that what you experienced means that the nose strut is low on fluid and it's time to service the nose strut. That means let out the air charge (after suspending the airplane so the nose gear is off the ground-usually done by using an engine hoist to lift off the lifting ring on the top of the engine) , then adding a fresh supply of hydraulic fluid and recharging the air to get the correct extension.
If you haven't had the strut fully serviced in a while it's a good time to remove the strut and the old o-ring seals; then install new seals and re-install the strut.
You should also get your mechanic to look at the torque links to see if the strut extension stop is worn. If it's worn, or the links are badly worn that will let the strut extend too far.
Let me know what you find,
Steve